Control device



April` 13, 1943.

l CONTROL ISIJVGE l J. J. lRcrl-lwr-f'LL j 2,316,626

2 Sheets-sheet 1 Filed Nov. 4,' 1940 INVENTOR.

MKM?, @imm April 13, 1943. I J. J. RoTHwELL l 2,316,526

CONTROL DEVICE:

Filed Nov. 4, y1940 2 sheets-sheet 2 A v f INVENTOR.

JzwJEoZQ/@ Patented Api. 13,1943;

maar@ coN'rnoL DEVICE John J. Rothwell, Elkhart, Ind.,- assignor-to PennElectric Switch Co., Goshen, Ind., a corporation of Iowa.

Application November 4, 1940, Serial No. 364,275

(Cl. 'J4-10) claims.

My invention relates to a tire inilater or other control device havingnovel stop means for an adjusting device for the range spring and meansto adjust the range spring for correcting its gradient.

. Oneaobject of my invention is to provide stop means for a range springadjusting means wherein the range spring adjusting means is adapted torotate through a, plurality of revolutions to cover the total range ofadjustment of the range spring, with the stop means being operated froman indicating dial for the range spring adjusting means and effective tostop rotation of the range spring adjusting means during one of itsrevolutions.

A further object is to provide a rock shaft having a stop arm for therange spring adjusting means and geared down means, such as anindicating dial for the range spring adjusting means,

my device whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in my claims and illustrated in theaccompanying drawings. Although the invention is susceptible-of avariety of embodiments, it is unnecessary to fully describe andillustrate more than one in order to give a full understanding oi. theinvention both from its structural and functional standpoints.Accordingly, I have illustrated a preferred and desirable embodiment ofthe invention in the accompanying drawings, in which:

Figure 1 is a. rear elevation of a tire iniiater embodying/my inventionshowing a. portion of the casing broken away to illustrate particularlythe range spring of the tire inflater or conefective to operate the rockshaft at the proper time to stop rotation of the range spring adjustingmeans in the desired position.

Still a further object is to provide a positive stop means which can beinstantly recognized as such when a predetermined position, such aszero, is reached, and the stop means being Operable to arrest all motionof the range spring adjusting means in a comparatively instantaneousmanner.

Still a further object is to provide stop means which is so designed asto eliminate strain on the parts, with the impact of operation of thestop means being absorbed through a stop arm mounted on arock shaft, therock shaft being operable by a geared down element of a range springadjusting crankshaft.

Still a further object is to provide a means to compensate for variationin gradient of theV range spring sothat an indicator can be set toaccurately indicate the 'adjustment of the range spring even though therange springs used in manufacture may vary in different installations.

More particularly, it is my object to provide a connection for a rangespring which consists lvice including a range spring III.

trol device;

Figure 2 is a diagrammatic view showing a range spring at zero pounds'pressure and illustrating by dotted v:lines an adjustment to compensatefor gradient variation;

Figure 3 is a similar view showing the range spring stretched foroperation at pounds' pressure, for instance;

Figure 4 'is an end elevation of the left hand end of Figure 1;

Figure 5 is a front elevation of a portion of the controller of Figure 4as looking in the direction of the arrow 5 5;

Figure 6 is a sectional view on the line 6-6 of Figure 5, and

Figure 7 is a similar view showing the part in a different position.

On the accompanying drawings I have used the reference character C toindicate generally a casing of a tire inilater or similar control de-The range spring I0 has at one end a loop I2 operatively connected witha control arm I3. Ai; the other end of the range spring a plug I 4,having a screw threaded portion I5, is operatively connected with thespring I0 by being screwed into the coils thereof. 'I'he plug Il is inthe form of a nut threaded on a crankshaft I6, which crankshaft isrotatable in a bearing I'I and has an operating crank I8 mountedthereon. The plug or nut Il is held against rotation by a pin I9projecting therefrom and slidably mounted in a slot 20 of a bracket 2 I.

I have found in commercial practice that a tolerance in springmanufacture of plus or minus five per cent exists. Accordingly, if a.range spring is to be loaded to sixty pounds, then errors of plus orminus three pounds would be encountered at the sixty-pound range,assuming that the instrument is accurate at the zerorange.

Therefore I have provided the spring I II with an adjustable gradientaccomplished by the screw threaded character of the portion I -of theplug` I4. By way of example, in Figure 2 the effective lengthof thespringA is indicated at L. If the spring is too stiff, its stiffness maybe relieved by increasing its effective length as.L', for example, byscrewing the plug I4 from its full line position to its dotted lineposition.

In the two instances illustrated, if the spring is now stretched acertain distance (T) to the position shown in Figure 3, a range fromzero to sixty pounds (arbitrarily taken) would be the result. If someindicating means is connected with the plug I4 to indicate the change insetting of the range spring, it would register some higher figure as,for instance, sixty-one or sixtyl two pounds, if the particularspringbeing used is too stiif. In that event, the plug I4 could be screwedoutwardly as to the dotted position so that with the same distance oftravel (indicated in this instance as T') there would be less variationin rangeand the spring would then register from zero to sixty pounds inaccordance with the indicating means which will hereinafter bedescribed. It is obvious that by a simple screw threaded connection ofthe plug I4 relative to the coils of the spring I0, the effective lengthof the spring, or in other words its stiffness, can be varied tocompensate for tolerances encountered in manufacture.

The indicating means which I show in connection with therange springadjusting crank I8 consists of aA countershaft 22 journaled as inbrackets 23 and 24. A gear 25 meshes with a pinion 26, the gear beingsecured to the countershaft 22 and the pinion to the crankshaft I6.Indicating dials 21, 28 and 29 are provided, the dial 21 being securedas by a pin 39 to the countershaft 22 and carrying the lowest digit ofthe series of dials. The dial 29 carries the highest digit, while thedial 28 carries the intermediate digits. v

In the usual manner of odometers and the like, a pair of special gears3I are provided, each having a single tooth 32 on one half and a seriesof ten teeth 33 on the. other half. The single teeth 32 mesh with singletooth gears 34 secured to the dials 21 and 28 and the ten teeth 33 ofeach gear 3| mesh with ten tooth gears 35 ofthe dials 28 and 29. 'I'husthe dial 28 is rotated one digit each revolution ,of the dial 21, andthe dial 29 is rotated one digit each ten revolutions of the dial 28.

A stop pin or abutment 36 is carried by the 4countershaft gear 25 and aistop arm 31 is provided therefor. The stop arm 31 is mounted on arockshaft 38 journaled in the brackets 23 and 24 and having'a crank pin38 provided with a reduced portion 40 passing through an arcuate slot 4Iof the bracket 24. The dial 29 has a cam 42 provided with a notch 43adapted at times to receive the reduced end 4I) of the crank pin 39. Aspring 44 is associated with the rock shaft 38 and tends to` rock it ina counterclockwise direction. I

During the adjustment of the crank I8 at any point above zero, the rockshaft 38 will assume the position shown in Figure 4 with the stop arm 31in its inoperative solid line position. The reduced end 40 of the crankpin 39, as shown in Figure 6, will during such adjustments assume aposition at the left hand end ofthe slot 4I under the action oi.' thelspring 44,' as shown in Figure 6. In Figure, the dial 29, forinstance',f

-is shown in its zero position. -,When the crank I8 is adjusted so thatdials 28 and'21 also show f zero, it is desirable thatv further movementof 5 the crank in a zero direction eifect operation 'of the stop arm 31.Accordingly, as the dials 29,

23 and 21 all tend to rotate backwards' to 999.

position, the cam 42 will move from the position of Figure 6 to thepositionl of Figure 7., so that l0 a side 43a of the slot 43 will engagethe reduced end 4I) of the crank pin 39 and swing it against the actionof the spring 44to the position ofFigure 1. 'I'his will effect movementof the arm 31 from its solid position to its dotted position of Figure4, so that it is directly in the path of the movement of the stop pin36. Accordingly, when the stop pin 36 reaches the arm.' the arm willtake the impact of stoppingby a thrust through the arm directly to therock shaft 38 and provide a positive stop against the crank I8 beingrotated any further in a receding direction. Thus I provide stop meansfor a range spring adjusting element, which element rotates through aplurality of revolutions through the range of ad- Justment of the springwith assurance of stopping at a predetermined position during one ofsuch revolutions. A

Although `I have shown my range spring compensating means and stop meansfor the adjusting mechanism of the rangespring in connection with a tireinfiater, it is obvious that these novel features can be used inconnection with any control device having a range spring or the likewhere it is desirable to compensate for variations m gradient and effecta stop of the adjusting means, when such adjusting means is of the typethat is rotated through greater than one revolution. Also, the cam 42 isconveniently operated by the indicating dial 29 but could be merely acam geared down relative to the adjusting shaft I6.

Changes .of the character just suggested, and4 others as well, may bemade without departing from the rear spirit and purpose of my invention,and it is my intention to cover by my claims any modified forms vofstructure or use of mechanical equivalents which may be reasonablyincluded within their scope wtihout sacrificing any of the advantagesthereof.

I claim as my invention:

shaft rotatable through a plurality of revolutions, a series ofindicating dials operatively connected with said crankshaft, 'and stopmeans for said crankshaft controlled by that one of said indicatingdials indicating the highest digit, said stop means comprising anabutment operatively connected with said crankshaft, a stop arm for saidabutment, a rock shaft having said stop arm mounted thereon, and meansfor swinging said rock shaft to stop position of said stop arm relativeto said abutment adjacent the zero position of said one of saidindicating dials, said one of said indicating dials having a cam notchto receive said rock shaft to effect such movement of said rock shaftand thereby to move said stop arm to stop position relative to saidabutment.

2. In a device of the class described, a shaft rotatable through aplurality of revolutions, a series of indicating dials operativelyconnected with said shaft, and stop means for said shaft controlled byone of said indicating dials, said stop means comprising an abutmentoperatively connected with said shaft, a stop element for 1. In a deviceof the class described, a crankl said abutment, and means for movingsaid stop element relative to said abutment, said one of said indicatingdials having a cam notch to effeet such movement; of said stop elementto stop position.

A3. In a device of the class described, a shaft rotatable through aplurality of revolutions, a

Acountershait geared to said ,iirst shaft and havlowest digit, the dialhaving the highest digit g being driven at less speed than said firstmentioned dial from said countershaft, stop means for said countershaftcontrolled by said last mentioned dial, said stop means comprising anabutment carried by said countershaft, a stop arm for said abutment, arock shaft having said stop arm mounted thereon, and means for swingingsaid rock shaft to stop position of said arm relative to said abutment,said last indicating dial having a cam notch to receive said rock shaftto effect such movement of said rock shaft and thereby of said rock armto stop position relative to said abutment.

. 5. In a device of the class described, adjusting means adapted torevolve through a pluralityof revolutions, stop means to stop therotation ofsaid adjusting means duringone such4 revolution, said stopmeans including a rock shaft carrying a pair of arms, one of said armsbeing movable to stop position, indicating means for 1 indicating theposition of adjustment of the adjusting means, said indicating meanshaving an indicating element geared down relative to said adjustingmeans and said indicating means having a cam coacting vwith the other ofsaid arms to rock said rock shaft, and thereby move said first arm toeffective stop position in one position of said geared down indicatingelement.

JOHN J. ROTHWELL.

